(a) Technical Field of the Invention
The present invention generally relates to a hinge, and more particularly to a multiple-stage positioning structure of synchronously rotatable dual shafts.
(b) Description of the Prior Art
With the progress and advance of science and technology, liquid crystal displays (LCDs) are now widely used as display devices of various electronic products.
LCDs have various advantages, such as high image quality, reduced size, light weight, low driving voltage, low power consumption, and wide applications, and are thus widely used in consumer electronic or computer devices, such as portable televisions, mobile phones, notebook computers, desktop display devices, and projection televisions, making them the main stream of display devices. Taking the notebook computers as an example, a liquid crystal display is mounted to a top cover so that when the notebook computer is being used, the top cover is lifted open to expose the liquid crystal display mounted thereto. The top cover and a computer host are coupled through hinges in order to allow the top cover to be closed and opened with respect to the computer host.
Thus, the hinges are one of the major factors that affect the product quality of the above-mentioned electronic products or computer products. To allow a display casing and a keyboard casing to be rotatable to an angular position desired by a user, the manufacturers have developed and proposed a dual-shaft hinge. However, the known dual-shaft hinges still have drawbacks in respect of structure and functionality.
In view of these problems, the present applicant has filed patent applications regarding multiple-angle synchronously rotatable dual shafts and a series of hinge related patents that help overcome the drawbacks of the conventional hinges have been granted. These hinges are rotatable under a predetermined tensioned condition to allow a user to rotate and turn to an angle that is desired by the user. However, if it is possible, during the rotation of the hinge, to set the hinge at a predetermined position, meaning to provide a positioning effect at the time when the top cover of a notebook computer is closed or opened to a predetermined location (such as the top cover being opened to a midway position), and to allow the hand of the use may sense such a positioning effect, then the use of the hinge can be further improved.